diff --git a/metagpt/actions/graph_db_action.py b/metagpt/actions/graph_db_action.py
new file mode 100644
index 000000000..d050760f6
--- /dev/null
+++ b/metagpt/actions/graph_db_action.py
@@ -0,0 +1,43 @@
+"""
+graph_db_action.py
+
+This module defines the GraphDBAction class, which interacts with a graph database.
+
+Classes:
+    GraphDBAction: An action class that interacts with a graph database.
+
+Usage Example:
+    action = GraphDBAction()
+    await action.load_graph_db('path/to/graph_db')
+
+    action = GraphDBAction(graph_db=external_graph_db)
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Optional
+
+from metagpt.actions import Action
+from metagpt.utils.di_graph_repository import DiGraphRepository
+from metagpt.utils.graph_repository import GraphRepository
+
+
+class GraphDBAction(Action):
+    """
+    An action class that interacts with a graph database.
+
+    Attributes:
+        graph_db (Optional[GraphRepository]): The graph database instance.
+    """
+
+    graph_db: Optional[GraphRepository] = None
+
+    async def load_graph_db(self, pathname: str | Path):
+        """
+        Asynchronously loads the graph database from the specified path.
+
+        Args:
+            pathname (str | Path): The path to the graph database file.
+        """
+        self.graph_db = await DiGraphRepository.load_from(pathname)
diff --git a/metagpt/utils/di_graph_repository.py b/metagpt/utils/di_graph_repository.py
index fee706ece..f8fabfbdc 100644
--- a/metagpt/utils/di_graph_repository.py
+++ b/metagpt/utils/di_graph_repository.py
@@ -23,8 +23,8 @@ from metagpt.utils.graph_repository import SPO, GraphRepository
 class DiGraphRepository(GraphRepository):
     """Graph repository based on DiGraph."""
 
-    def __init__(self, name: str, **kwargs):
-        super().__init__(name=name, **kwargs)
+    def __init__(self, name: str | Path, **kwargs):
+        super().__init__(name=str(name), **kwargs)
         self._repo = networkx.DiGraph()
 
     async def insert(self, subject: str, predicate: str, object_: str):
@@ -112,8 +112,14 @@ class DiGraphRepository(GraphRepository):
     async def load(self, pathname: str | Path):
         """Load a directed graph repository from a JSON file."""
         data = await aread(filename=pathname, encoding="utf-8")
-        m = json.loads(data)
+        self.load_json(data)
+
+    def load_json(self, val: str):
+        if not val:
+            return self
+        m = json.loads(val)
         self._repo = networkx.node_link_graph(m)
+        return self
 
     @staticmethod
     async def load_from(pathname: str | Path) -> GraphRepository:
@@ -126,9 +132,7 @@ class DiGraphRepository(GraphRepository):
             GraphRepository: A new instance of the graph repository loaded from the specified JSON file.
         """
         pathname = Path(pathname)
-        name = pathname.with_suffix("").name
-        root = pathname.parent
-        graph = DiGraphRepository(name=name, root=root)
+        graph = DiGraphRepository(name=pathname.stem, root=pathname.parent)
         if pathname.exists():
             await graph.load(pathname=pathname)
         return graph